GEAR-DIFFERENTIAL BEVEL 9C9748 - Caterpillar

Check for the proper version of the regulator.
Check the part number of the digital voltage regulator. Refer to the chart in Testing And Adjusting, "Troubleshooting". Check whether the digital voltage regulator is proper for the application.Expected Result: The digital voltage regulator is proper for the application.Results:
OK: Go to Step 2.
NOT OK: Install the proper digital voltage regulator. STOP.
Check the status of the display.
Stop the generator set.
Observe the display on the digital voltage regulator.Expected Result: The display should contain a number.Results:
OK: Proceed to Step 4.
NOT OK: No number is present on the display. Proceed to Step 3.
Check the DC voltage.
Check for proper DC voltage from terminal "B+" to "B-". The acceptable voltage range is 18 VDC to 32 VDC.Expected Result: The sufficient DC voltage is present.Results:
OK: The sufficient DC voltage is present. Remove the DC power wires from terminals "B+" and "B-" for 30 seconds. Reconnect the DC power wires to the "B+" and "B-" terminals. If the regulator display is still blank, the regulator is faulty. Then, the regulator needs to be replaced. If this condition has occured, verify that the correct burden resistor or rheostat is connected between the droop current transformer and the regulator. If no resistor is present, the regulator was destroyed because of high current on the CT input. Refer to Testing And Adjusting, "Wiring Diagrams". STOP.
NOT OK: The sufficient DC voltage is not present. Repair the supply voltage wiring, fuses and circuit breakers as necessary. STOP.
Verify the proper configuration of the parameters.Pay particular attention to parameters :01, :02, and :15.
If the rated voltage, parameter :01 is increased, the output voltage will increase.
If the sensing transformer ratio, parameter :02 is increased, the output voltage will decrease.
If the voltage gain (line loss compensation), parameter :15 is increased, the output voltage will increase when the generator output current increases. Try the default value.
If generator type is set incorrectly, the regulator may operate constantly in the under frequency curve. Check parameter :50 and compare actual frequency to verify.
Display the number in parameters :92, :93, and :95 (if present). A display of "0000" indicates no faults. If a fault code is present, see System Operation, "Parameters".Expected Result: The problem has been resolved.Results:
OK: The problem has been resolved. STOP.
NOT OK: The problem has not been resolved. Proceed to Step 5.
Check the PM inputs.
Turn the engine off.
Check that all of the digital voltage regulator connections are tight and properly made per the appropriate wiring diagram.
Check PM fuses (connecting to terminals 26 and 30 of the digital voltage regulator).
Restart the engine.
Check the PM inputs (26, 28, and 30) of the digital voltage regulator. Measure the AC voltage between terminals 26 to 28, 28 to 30, and 26 to 30.
If the digital voltage regulator is connected as a self-excited regulator, check if the power transformers are properly wired as an open delta configuration for the according wiring diagrams. Check if the power transformers are properly sized in order to provide a minimum of 1200 VA each.Expected Result: The proper voltage is approximately